Fastest sailboats in modern times

[GiTS]

I've been looking at the fastest sailboats in modern times and I've been wondering a few things.
Why does the front sail have no boom but the back sail does?
Why do racing boats have http://en.wikipedia.org/wiki/Image:Parts_of_a_sail.svg" kinds of sails?
A lateen sail has more area and doesn't require such a tall mast. Wouldn't it be more stable to use these?
Why are hulls shaped with concave curves when veiwed head on? Wouldn't a rounded convex curve be more hydrodynamic?

 

[jdg812]

Why does the front sail have no boom but the back sail does?

Front sail goes from side to side when the boat changes direction. Front sail with boom cannot cross the mast.

A lateen sail has more area and doesn't require such a tall mast. Wouldn't it be more stable to use these?

Wind speed is zero at h = 0 and increases with height so that generally the taller the mast, the faster the wind around tha sail.

 

[russ_watters]

I'm not sure I understand the third question. The bottom of a big racing sailboat hull is convex shaped, kinda like half a peanut.

Or are you talking about small flat-bottomed one-seaters? Those hulls are planing hulls - they ride above their wake for more speed.